As Europe continued to digest the shock of Britain’s vote to leave the European Union, foreign ministers of the EU’s six founding members – Germany, France, Italy, Belgium, Luxembourg and the Netherlands – met in Berlin Saturday to formulate a response.

European integration has taken a painful blow, but the bloc’s core members insist it won’t be fatal.

"We have to have the opportunity now to take care of Europe and its future. That means after the decision Great Britain made, negotiations on a British exit, or Brexit, should begin as soon as possible," Germany’s foreign minister, Frank-Walter Steinmeier, told reporters after the meeting.

British Prime Minister David Cameron will travel to Brussels Tuesday. The following day, the 27 remaining member states will meet for the first time without Britain at the table.

Their differences won’t make for an easy settlement, said Tim Oliver, a political professor at the London School of Economics.

“It’s not going to be quick, it’s not going to be easy," he said, "and it’s going to throw up lots of opportunity for division and bitterness not just between the UK and the EU, but within British government and British politics, and within the remaining EU member states.”

Britain's Prime Minister David Cameron speaks after Britain voted to leave the European Union, as his wife Samantha watches outside Number 10 Downing Street in London, Britain, June 24, 2016.

Announcing his resignation in the wake of the Brexit vote, Cameron said the negotiations should be handled by his successor, who should be chosen by October. However, EU officials and heads of state want the talks to start immediately.

Head of the European Commission Jean-Claude Juncker said the British exit would not be "an amicable divorce," but noted there never had been a "deep love affair."

German business leaders have already said they don’t want trade barriers on Britain, one of their biggest markets. But any concessions might encourage other members to follow Britain’s lead, said Oliver.

"How does Germany respond to a situation where one of its largest trading partners has decided to leave the single market? Will it prioritize economic links? But if it does, it risks damaging the political unity and the ideas. So the EU is going to struggle to find unity in balancing those two."

Finding that balance will be a big test of Europe’s ability to survive Britain’s rejection.